Redshift-space Distortions of the Power Spectrum of Cosmological Objects on a Light Cone : Explicit Formulations and Theoretical Implications

We examine the effects of the linear and the cosmological redshift-space distortions on the power spectrum of cosmological objects on a light cone. We develop theoretical formulae for the power spectrum in linear theory of density perturbations in a rigorous manner starting from first principle corresponding to Fourier analysis. Approximate formulae, which are useful properly to incorporate the redshift-space distortion effects into the power spectrum are derived, and the validity is examined. Applying our formulae to galaxy and quasar samples which roughly match the SDSS survey, we will show how the redshift-space distortions distort the power spectrum on the light cone quantitatively.Comment: 30 pages, Accepted for publication in the Astrophysical Journal Supplement Serie

Reflecting on the Physics of Notations applied to a visualisation case study

This paper presents a critical reflection upon the concept of 'physics of notations' proposed by Moody. This is based upon the post hoc application of the concept in the analysis of a visualisation tool developed for a common place mathematics tool. Although this is not the intended design and development approach presumed or preferred by the physics of notations, there are benefits to analysing an extant visualisation. In particular, our analysis benefits from the visualisation having been developed and refined employing graphic design professionals and extensive formative user feedback. Hence the rationale for specific visualisation features is to some extent traceable. This reflective analysis shines a light on features of both the visualisation and domain visualised, illustrating that it could have been analysed more thoroughly at design time. However the same analysis raises a variety of interesting questions about the viability of scoping practical visualisation design in the framework proposed by the physics of notations

Comparison of 99mTc-sestamibi and doxorubicin to monitor inhibition of P-glycoprotein function

P-glycoprotein (Pgp) overexpression is a well-recognized factor in resistance to chemotherapy. Doxorubicin flow cytometry is used to monitor Pgp function in haematological specimens and biopsies from other cancers, and radionuclide imaging with sestamibi has recently shown promise for non-invasive monitoring. In the present study the two methods were directly compared in single-cell suspensions of three variants of the human breast carcinoma cell line MCF7: sensitive MCF7/WT, doxorubicin-selected MCF7/AdrR, and MDR1 -gene-transfected MCF7/BC19 cells with doxorubicin resistance factors of 1, 192, and 14, respectively. Accumulation of sestamibi and mean fluorescence of doxorubicin (5.5 μM) were assessed over 60 min in the presence and absence of Pgp modulators GG918 (0.01 to 0.2 μM) and PSC833 (0.05 to 2.0 μM). Accumulation curves for sestamibi and doxorubicin differed among the cell variants under control conditions, with sestamibi showing a significantly greater difference between WT and resistant cells than doxorubicin. Both GG918 and PSC833 reversed uptake deficits to WT levels for sestamibi in MCF7/BC19 cells and doxorubicin in MCF7/BC19 and MCF7/AdrR cells, but failed to show the same effect for sestamibi in MCF7/AdrR cells (∼30% of MCF7/WT level). Thus, both methods clearly distinguished sensitive from resistant MCF7 variants, with the radionuclide method showing greater sensitivity. © 2001 Cancer Research Campaign http://www.bjcancer.co

Comparing behavior under risk and under ambiguity in a lifecycle experiment

Experiments on intertemporal consumption typically show that people have difficulties in optimally solving such problems. Previous studies have focused on contexts in which agents are faced with risky future incomes and have to plan over long horizons. We present an experiment comparing decision making under certainty, risk, and ambiguity, over a shorter lifecycle. Results show that behavior in the ambiguity treatment is markedly different than in the risk condition and it is characterized by a significant pattern of under-consumption

Non-linear Evolution of Baryon Acoustic Oscillations from Improved Perturbation Theory in Real and Redshift Spaces

We study the non-linear evolution of baryon acoustic oscillations in the matter power spectrum and correlation function from the improved perturbation theory (PT). Based on the framework of renormalized PT, we apply the {\it closure approximation} that truncates the infinite series of loop contributions at one-loop order, and obtain a closed set of integral equations for power spectrum and non-linear propagator. The resultant integral expressions keep important non-perturbative properties which can dramatically improve the prediction of non-linear power spectrum. Employing the Born approximation, we then derive the analytic expressions for non-linear power spectrum and the predictions are made for non-linear evolution of baryon acoustic oscillations in power spectrum and correlation function. A detailed comparison between improved PT results and N-body simulations shows that a percent-level agreement is achieved in a certain range in power spectrum and in a rather wider range in correlation function. Combining a model of non-linear redshift-space distortion, we also evaluate the power spectrum and correlation function in correlation function. In contrast to the results in real space, the agreement between N-body simulations and improved PT predictions tends to be worse, and a more elaborate modeling for redshift-space distortion needs to be developed. Nevertheless, with currently existing model, we find that the prediction of correlation function has a sufficient accuracy compared with the cosmic-variance errors for future galaxy surveys with volume of a few (Gpc/h)^3 at z>=0.5.Comment: 25 pages, 15 figures, accepted for publication in Phys.Rev.

Baryon Acoustic Oscillations in 2D: Modeling Redshift-space Power Spectrum from Perturbation Theory

We present an improved prescription for matter power spectrum in redshift space taking a proper account of both the non-linear gravitational clustering and redshift distortion, which are of particular importance for accurately modeling baryon acoustic oscillations (BAOs). Contrary to the models of redshift distortion phenomenologically introduced but frequently used in the literature, the new model includes the corrections arising from the non-linear coupling between the density and velocity fields associated with two competitive effects of redshift distortion, i.e., Kaiser and Finger-of-God effects. Based on the improved treatment of perturbation theory for gravitational clustering, we compare our model predictions with monopole and quadrupole power spectra of N-body simulations, and an excellent agreement is achieved over the scales of BAOs. Potential impacts on constraining dark energy and modified gravity from the redshift-space power spectrum are also investigated based on the Fisher-matrix formalism. We find that the existing phenomenological models of redshift distortion produce a systematic error on measurements of the angular diameter distance and Hubble parameter by 1~2%, and the growth rate parameter by ~5%, which would become non-negligible for future galaxy surveys. Correctly modeling redshift distortion is thus essential, and the new prescription of redshift-space power spectrum including the non-linear corrections can be used as an accurate theoretical template for anisotropic BAOs.Comment: 18 pages, 10 figure

Anti-proliferative activity of oral anti-hyperglycemic agents on human vascular smooth muscle cells: thiazolidinediones (glitazones) have enhanced activity under high glucose conditions

Background: Inhibition of vascular smooth muscle cell (vSMC) proliferation by oral anti-hyperglycemic agents may have a role to play in the amelioration of vascular disease in diabetes. Thiazolidinediones (TZDs) inhibit vSMC proliferation but it has been reported that they anomalously stimulate [3H]-thymidine incorporation. We investigated three TZDs, two biguanides and two sulfonylureas for their ability of inhibit vSMC proliferation. People with diabetes obviously have fluctuating blood glucose levels thus we determined the effect of media glucose concentration on the inhibitory activity of TZDs in a vSMC preparation that grew considerably more rapidly under high glucose conditions. We further explored the mechanisms by which TZDs increase [3H]-thymidine incorporation. Methods: VSMC proliferation was investigated by [3H]- thymidine incorporation into DNA and cell counting. Activation and inhibition of thymidine kinase utilized short term [3H]- thymidine uptake. Cell cycle events were analyzed by FACS

The Challenges of Living with and Caring for a Child or Children Affected by Neuronal Ceroid Lipofuscinosis Type 2 Disease: In-Depth Family Surveys in the United Kingdom and Germany

Limited research has investigated the challenges faced by families caring for children with neuronal ceroid lipofuscinosis type 2 (CLN2) disease. Face-to-face, mixed-method, in-depth surveys were conducted with 19 families (23 children) in the UK (n=9) and Germany (n=10) to assess the impact of caring for children with CLN2 disease, using national wellbeing and quality of life (QoL) measures. Primary (n=19) and secondary (n=10) caregivers, adult siblings (n=2), and child siblings (n=2) were included. Caregivers reported reduced health-related QoL compared with age and gender-matched controls (mean utility scores 0.08 and 0.11 lower in Germany and the UK, respectively). Hours of caregiving were significantly higher relative to that provided to a child of normal health, with stress, back pain, and reductions in sleep being recorded. Lower life satisfaction and happiness with partners were also reported, along with significant financial burden. Those caring for children in the late stage of disease were more greatly impacted than those with children in the rapidly progressive stage, or who were bereaved. The results of this study make clear the importance of emotional and practical support for caregivers and siblings coping with CLN2 disease

Lessons learned on closed cavity thermophotovoltaic system efficiency measurements

Previous efficiency measurements have highlighted that to accurately measure and predict thermophotovoltaic (TPV) integrated cell or array efficiencies, a thorough understanding of the system is required. This includes knowledge of intrinsic diode and filter characteristics, radiative surface properties of all materials used within the cavity, and an intimate knowledge of the radiator/photon source. As a result of these and other lessons learned, the cavity test fixture used in earlier experiments was redesigned. To reduce radiator temperature gradients, the radiator was oversized and thickened, cavity walls were eliminated, the diode heat sink and shielding material were separated, and the cold side was redesigned to incorporate a steady state heat absorbed measurement technique. This redesigned test fixture provides an isothermal radiator and significantly enhances calorimetry capabilities. This newly designed cavity test fixture, in conjunction with the Monte Carlo Photon Transport code RACER-X, was used to improve and demonstrate the understanding of in-cavity TPV diode/module system efficiency testing. A single TPV diode was tested in this new fixture and yielded good agreement between measurements and predictions